Support structures, commonly referred to as brackets, that are used to connect various engine components to other components on the engine are known. Brackets are typically used to mount onto a base engine structure, for example a crankcase, other engine components that are necessary for the operation of the engine. Such components that are typically mounted onto the base engine structure include turbochargers, Exhaust Gas Recirculation (EGR) coolers, oil coolers, electronic control modules (ECM), oil filters, and so forth.
Brackets used to mount components onto an engine are typically designed to comport with appropriate specifications that require that the mounting of the component does not subject the components to excessive vibration. As is known, engines generate vibrations during operation that may negatively affect components that are connected thereto.
Mechanical structures inherently posses a natural vibration frequency that is exhibited at times when the structures are vibrationally excited along one or more directions. These natural frequencies, or modes, are vibrations that cause a maximum amplitude of vibration along an axis of excitation. Components vibrating at or close to their natural frequency experience increased amplitudes and increased accelerations, both of which are undesirable and detrimental to the component's operation and longevity of service.
When an engine operates, the vibrational excitation it produces is measurable and quantifiable. The vibrational input an engine will impart to components that are mounted thereto is typically analogous to a range of engine speeds the engine is capable of operating under. Similarly, the natural frequencies of various components in their as-mounted state on the engine is determinable with experimentation or simulation. A specification for mounting a component onto an engine will typically specify that the natural frequency of the component, as mounted on the engine, should fall outside of the expected range of vibration that the engine will produce during operation.
In situations where the natural frequency of a component falls within the range of expected vibrations the engine will produce during operation, one typically engages in an iterative process of design and simulation that will produce a bracket design that can increase or reduce the natural frequency of a system that includes the bracket and the component such that it falls outside of the expected range of vibrational input from the engine into the component. Brackets are usually designed such that their rigidity is increased so that their natural frequency increases enough to fall outside of the maximum frequency of excitation the engine is expected to produce.
Even though brackets that are designed stiffly enough to increase their natural frequency to fall outside of the range of excitation frequencies of the engine are effective at reducing or eliminating excessive vibration of components, such brackets are often relatively larger and heavier than what is required to maintain component mounting in a static condition. Large and heavy brackets cause an increase in cost of manufacture of an engine and a decrease in fuel economy of the engine due to their larger size and weight.